Here are some additional facts that may be relevant:
- before the migration each site had its own database. Now they share a single database using different table prefixes
- the 1.6.1+ site is unicode; the 1.6.3+ site needs unicode conversion
Humm...interesting set-up. What hosting company are you using John?
It really doesn't "cost" anything to use separate databases and it would be a lot "cleaner" set-up to keep them separate.
I have about fifteen 1.6+ installs on a dedicated server and don't have that problem with any of them...of course, none of them share the same database...there is really no reason for it since as the server admin, I can create as many databases as I want.
If I told you, I'd have to enter the witness protection program
Ha...enough said .
Good luck...with that type set-up, I'd ask for a discount!...uh, no, check that, I'd look for a new hosting company.